(a) Field
The present disclosure relates to a liquid crystal display and a manufacturing method thereof.
(b) Description of the Related Art
A liquid crystal display is a type of flat panel display that is widely used today. The liquid crystal display includes two display panel sheets in which field generating electrodes such as pixel electrodes and common electrodes are formed, and a liquid crystal layer interposed between the display panels. In the liquid crystal display, a voltage is applied to the field generating electrodes to generate an electric field in the liquid crystal layer. The electric field determines the alignment direction of liquid crystal molecules of the liquid crystal layer, and an image is displayed by controlling the polarization of incident light.
Among the LCDs, a vertical alignment (VA) mode LCD, which aligns LC molecules such that their long axes are perpendicular to the panels in the absence of an electric field, is receiving much attention. VA mode LCDs offer high contrast ratio and wide reference viewing angle.
In the vertical alignment (VA) mode liquid crystal display, to obtain the wide viewing angle, a plurality of domains in which the alignment directions of the liquid crystal molecules are different may be formed in one pixel. As such, as a means of forming the plurality of domains, a method of forming cutouts such as minute slits in the field generating electrode or forming protrusions on the field generating electrode, is used. In this method, the liquid crystals are aligned in a direction that is vertical to a fringe field by the fringe field formed between an edge of the cutout or the protrusion and the field generating electrode facing the edge, and thus a plurality of domains may be formed.
The vertically aligned (VA) mode liquid crystal display has poor lateral surface visibility as compared to front surface visibility, and in order to solve this, a method of dividing one pixel into two sub-pixels and making voltages of the two sub-pixels different is proposed.
Meanwhile, in order to implement the wide viewing angle and increase a response speed of the liquid crystals, a method of allowing the liquid crystals to have a pretilt in a state where an electric field is not applied has been developed. In order to allow the liquid crystals to have the pretilt in various directions, the pretilt may be formed by using an alignment layer where alignment directions are various or adding a reactive mesogen to the alignment layer or the liquid crystal layer and then irradiating light in a state where the electric field is applied.
Recently, to meet a demand for a large-sized liquid crystal display device and increase viewer's immersion and tension, curved displays have been introduced to the market. An edge of the display panel is fixed by a sealant. Therefore, when the display panel is bent, buckling occurs at a middle portion of the panel, such that alignment between two display plates of the display panel may be mismatched. This misalignment causes directions of pretilts, which are formed on the two display plates in a plurality of same directions, partially deviate from each other and form dark parts such as texture in a pixel, reducing display quality.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.